摘要
针对低速π/4-DQPSK差分解调过程中因大频偏导致的性能恶化问题,提出了一种基于相关峰检测的频差估计算法。该算法利用已知发送的M序列对接收信号进行相关检测,根据频偏对同相(I)和正交(Q)两路相关峰值的不同影响进行频偏估计。给出了该算法的理论推导,并将其与传统的Kay估计、Fitz估计、L&R估计进行仿真对比。结果表明,该算法估计范围相当,为符号速率的一半;估计精度略差,信噪比大于0 d B时均方误差优于2×10-4,但显著降低了运算量与实现复杂度,具有很好的工程实用价值。
A frequency offset estimation algorithm based on correlation peak detection is presented to solve the low symbol-rateπ/4-DQPSK differential demodulation performance deterioration due to large frequen-cy offset. This algorithm correlatively detects the received signal using known M sequence and the frequen-cy offset is estimated based on the diffident effect on the correlation peak of inphase( I) channel and quad-rature( Q) channel. Theoretical derivation of the algorithm is given and its capability is simulated and com-pared with Kay estimation,Fitz estimation and L&R estimation. Results show that this algorithm has similar estimation range which is half of symbol rate,slightly poorer estimation precision whose mean-square error ( MSE) is superior than 2 ×10-4 with signal-to-noise ratio( SNR) greater than 0 dB ,but much less calcu-lating amount and implementation complexity. It is more valuable in practical engineering.
出处
《电讯技术》
北大核心
2015年第9期1036-1041,共6页
Telecommunication Engineering
基金
国家自然科学基金资助项目(61301158)~~
关键词
跳频通信
π/4-DQPSK差分解调
频差估计
相关峰检测
frequency hopping communication
π /4-DQPSK differential demodulation
frequency offset estimation
correlation peak detection
